The present invention relates to an electronic apparatus for a vehicle and, for example, to a sound apparatus for a vehicle, which allows an operator to integrally operate players (playback devices) of a cassette tape, CD, MD, and the like at a control panel.
Conventionally, in an automobile as a representative vehicle, various electronic apparatuses are equipped, and as an example of such sound apparatus for a vehicle, Japanese Patent Laid-Open No. 11-31087 previously filed by the present applicant discloses an electronic apparatus in which a center module for systematically controlling a plurality of electronic units such as an air-conditioner control module, car audio control module, and the like diagnoses failures of these electronic units, and displays a message upon detecting any failures.
An example of an electronic apparatus disclosed in an embodiment of the specification of the previous application for the purpose of reducing development cost required for realizing a failure diagnosis function, and improving failure diagnosis precision will be briefly explained below.
That is, in an embodiment of the previous application shown in FIG. 13 (FIG. 9 of the previous application), the detection value of a room temperature sensor 151 is input to a center module electronic control unit (ECU) 108, and the detection value of a room temperature sensor 152 is input to an air-conditioner ECU 121 via an air-conditioner mechanism 122.
The center module ECU 108 outputs the detection value detected by the room temperature sensor 151 to the air-conditioner ECU 121, and executes predetermined arithmetic processes using that detection value.
The air-conditioner ECU 121 executes the same arithmetic processes as the predetermined arithmetic processes using the detection value of the room temperature sensor 151 acquired via the center module ECU 108, and the detection value of the room temperature sensor 152 acquired via the air-conditioner mechanism 122, and sends these arithmetic process results to the center module ECU 108.
The center module ECU 108 compares arithmetic process results computed by itself and those acquired from the air-conditioner ECU 121, and determines that some failure has occurred in the air-conditioner ECU 121 or air-conditioner mechanism 122 if these results do not match.
Japanese Patent Publication No. 61-32173 and U.S. Pat. No. 4,497,057 as its corresponding U.S. application propose an abnormality display device in which a plurality of control units for controlling the behaviors of a vehicle such as anti-skid control, engine combustion control, vehicle velocity control, and the like make self diagnosis, and failure information detected by these control unit is sent to a management device which integrally stores and displays the failure information of the respective control units.
According to the former prior art, when any failure has occurred, a passenger can be alerted to it. However, since the state of the failure is not preserved, a service station such as a dealer or the like cannot quickly find the failure that has occurred on the basis of verbal information given by the customer.
By contrast, according to the latter prior art, since the internal memory of the management device integrally stores failure information, a cause of the failure can be easily found upon maintenance by reading out the information stored in the memory.
However, since the memory size is limited, if new failure information is stored in the memory as a result of failure diagnosis which is done by a service person for maintenance, the required failure information may be deleted and, hence, the apparatus cannot fully assist failure diagnosis upon maintenance.
Also, when the memory is added for the purpose of storing only failure-information, a cost reduction is disturbed.
When a given failure has occurred, information required by a service person is not always required by a passenger.
Assume that a given function has failed, and other functions are still operable. In this case, if information that pertains to the failure is always displayed, the convenience impairs. This is particularly the case when an electronic apparatus to be monitored, which does not pose any fatal failure against safe running of a vehicle, e.g., a sound apparatus such as a car stereo system or the like, has failed.
The present application pays attention to a sound apparatus which is most popular among electronic apparatuses for a vehicle and includes, e.g., a cassette tape playback device, radio receiver, and the like, and has as its object to integrally store failure information that has occurred in various sound playback units which construct the sound apparatus.
In order to achieve the above object, a sound apparatus for a vehicle according to the present invention is characterized by the following arrangement.
That is, a sound apparatus for a vehicle, which comprises a control panel (10) provided with operation switches that can operate a display device and a sound playback unit, a sound playback unit (20, 30) which is independent from the control panel and plays back sound information in a predetermined information format and a control unit (40) which is independent from the control panel, and controls operation of the sound playback unit in accordance with an operation signal input from the operation switch, is characterized in that the sound playback unit (20, 30) makes self diagnosis of predetermined items therein, and outputs the diagnosis result to the control unit via a communication line, and the control unit makes self diagnosis of predetermined items therein, and stores at least failure information of the diagnosis result thereof and the diagnosis result input from the sound playback unit in a nonvolatile memory (48) provided thereto.
Alternatively, as another sound apparatus for a vehicle that can achieve the aforementioned object, a sound apparatus for a vehicle, which comprises a control panel (10) provided with operation switches that can operate a display device and a sound playback unit on one surface facing a passenger room, a sound playback unit (20, 30) which is disposed as one component on the other surface of the control panel and plays back sound information pre-stored in a storage medium and a control unit (40) which is disposed as one component on the other surface of the control panel, has a radio tuner (47) as another sound playback unit, and controls playback operations of the radio tuner and the sound playback unit in accordance with an operation signal input from the operation switch, is characterized in that the sound playback unit makes self diagnosis of predetermined items therein, and outputs the diagnosis result to the control unit via a communication line, and the control unit makes self diagnosis of predetermined items including operation of the radio tuner therein, and stores at least failure information of the diagnosis result thereof and the diagnosis result input from the sound playback unit in a nonvolatile memory (48) provided thereto.
With both the sound apparatuses for a vehicle with the above arrangements, failure information that has occurred in each of various sound playback units which construct the sound apparatus for a vehicle can be integrally stored in the control unit which controls these sound playback units.
In a preferred embodiment, if the sound apparatus for a vehicle with either arrangement uses, as the nonvolatile memory, a nonvolatile memory for storing a password which can restrict unauthorized access to the sound apparatus for a vehicle, a cost reduction can be achieved by sharing the nonvolatile memory.
Alternatively, in the arrangement of the other sound apparatus for a vehicle, if a nonvolatile memory for storing frequency information to be received by the radio tuner is used as the nonvolatile memory, a cost reduction can be achieved by sharing the nonvolatile memory.
In either apparatus arrangement, the control unit also controls display operation of the display device, and displays failure information stored in the nonvolatile memory on the display device in accordance with a predetermined operation input at the control panel. With this arrangement, the state of failure that occurred previously can be checked quickly.
For example, the sound apparatus for a vehicle can mount as the sound playback unit an arbitrary sound playback unit selected from a plurality of different sound playback units of different manufacturers or models, and the control unit displays identification information which can specify a manufacturer or model of the sound playback unit which is selected in advance and mounted as the sound playback unit in association with the failure information when the failure information is displayed on the display device in response to the predetermined operation input at the control panel. With this arrangement, even in the sound apparatus for a vehicle that allows various system arrangements, the system arrangement of the sound apparatus which differs in units of users can be easily recognized upon checking the failure state.
For example, the sound apparatus for a vehicle can mount as the sound playback unit an arbitrary sound playback unit selected from a plurality of different sound playback units of different manufacturers or models, the sound playback unit outputs identification information that can specify a manufacturer or model of the sound playback unit together with the diagnosis result upon outputting the diagnosis result to the control unit, and the control unit stores the failure information and identification information in the nonvolatile memory, also controls display operation of the display device, and displays the failure information and identification information in association with each other in response to a predetermined operation input at the control panel. With this arrangement, even in the sound apparatus for a vehicle that allows various system arrangements, the system arrangement of the sound apparatus which differs in units of users can be easily recognized upon checking the failure state.
For example, the sound playback unit includes a plurality of sound playback units for playing back storage media of different formats, and when a failure has occurred in one of communication lines to the plurality of sound playback units as one of the predetermined self diagnosis items, the control unit stores information that can specify the communication line which has suffered the failure in the nonvolatile memory. In this case, the control unit preferably inhibits failure diagnosis of the communication lines until predetermined initial start operation thereof is completed. In this way, a sound playback unit which can normally operate even when it has failed partially can continue its playback operation.
For example, when input operation for operating the disabled sound playback unit corresponding to the failure information stored in the nonvolatile memory is made at the control panel, the control unit displays on the display device information indicating that the sound playback unit has failed. In this manner, a passenger can be alerted to the failed sound playback unit using failure information integrally stored in the nonvolatile memory. With this alarm, the failure state can be prevented from worsening by passenger""s forcible operation, and the passenger can quickly select another available function without repeating wasteful operations.
For example, when operation for operating the disabled sound playback unit corresponding to the failure information stored in the nonvolatile memory is input at the control panel, the control unit inhibits operation control of that disabled sound playback unit. With this arrangement, since optimal control is done in correspondence with the failure state, deterioration of operability upon failure can be minimized.
For example, when a control signal is received from the sound playback unit, the control unit executes a predetermined process according to the control signal, and when the control signal is received from the disabled sound playback unit corresponding to the failure information stored in the nonvolatile memory, the control unit inhibits execution of the predetermined process for the disabled sound playback unit. With this arrangement, since optimal control is done in correspondence with the failure state, deterioration of operability upon failure can be minimized.
Other features and advantages of the present invention will be apparent from the following description taken in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the figures thereof.